US Patent 9039551 Rear derailleur device for a bicycle shifting system

A derailleur device, particularly a rear derailleur, includes at least one locking device for locking a chain guide at least in one locking position that is different from the starting position in relation to a movable element, and it is provided therein that the locking device includes a locking element displaceable between a passive position, in which the chain guide is released in relation to the movable element, and at least one active position, in which the chain guide is held in the at least one locking position.